This invention relates to a method and apparatus for detecting the leakage of radioactive gas from a fuel assembly of a nuclear reactor. In particular, the present invention concerns a novel method of simultaneously testing a plurality of fuel rod assemblies to determine which, if any, are giving off radioactive gas produced in leaking fuel rods
While detecting devices have been used with nuclear reactors, known detectors have proven both complex and inefficient. For example, U.S. Pat. No. 3,762,993 issued Oct. 2, 1973 to Jones provides a complex detection assembly which separates several of the fuel rod assemblies for testing by lifting them from the reactor core. Since only one or a few of the fuel rod assemblies can be lifted at a time, the total testing time is relatively great, particularly if all of the fuel rod assemblies in the reactor core are examined. Because the reactor must be shut down during the testing period, the prolonged time required for testing by the Jones device has proven to be very costly with respect to the efficient operation of the reactor.
As will be discussed in detail hereinafter, applicant's new and useful invention solves the problems confronting Jones' and similar known devices, while at the same time providing a novel method and apparatus for simultaneously testing all of the fuel rod assemblies for leakage of radioactive gas. The present invention is capable of identifying which fuel rod assemblies, if any, are leaking radioactive gas without the need for physically separating individual fuel rod assemblies from the nuclear core.